When traveling by motor home (hereinafter “towing vehicle”), it is often desirable to tow another vehicle. The towed vehicle is essentially dead weight that pushes the towing vehicle when the operator tries to slow or stop, which can limit the life span, cause decreased performance or cause failure of the towing vehicle's brakes. One way to solve this problem is to brake the towed vehicle in conjunction with the towing vehicle so that its brakes do not have to compensate for the additional momentum of the towed vehicle. Thus the overall load felt by the towed vehicle's brakes is reduced and their life span is increased.
Various methods of braking the towed vehicle in conjunction with the towing vehicle are known in the art. For example, self-contained auxiliary or supplemental braking apparatus are common and require no permanent installation in the towed vehicle. Rather, such auxiliary braking apparatus are positioned on the floorboard of the towed vehicle and employ an actuator arm, such as a pneumatic or hydraulic cylinder/piston arm, electric screw, etc. to selectively depress the brake pedal of the towed vehicle.
Some auxiliary braking apparatus use an RF signal to provide information to the operator of the motor home. For example, information related to the braking or towing status of the towed vehicle is often transmitted to an operator of the towing vehicle from the auxiliary braking apparatus to a remote unit located in the towing vehicle. While this information may be useful, the operator remains uninformed about equally important issues, such as whether the supplemental braking system is functioning efficiently within desired parameters. Thus there is a need for an auxiliary brake apparatus that transmits diagnostic information related to the auxiliary braking apparatus and the towed vehicle to the operator of the towing vehicle.
One drawback of auxiliary braking systems of the art is that none allow the operator to control particular braking parameters. As such, once the operator has designated brake settings on the auxiliary braking apparatus, the towing vehicle must be stopped so that the operator can make adjustments to the auxiliary braking apparatus. Thus there is a need for a system that allows the operator of the towing vehicle to remotely adjust certain parameters of the auxiliary braking apparatus, such as braking pressure, braking sensitivity, etc. from the towing vehicle.
Since the auxiliary brake apparatus is not located in the towing vehicle and typically the towed vehicle is unoccupied while in transit, the operator is generally unaware of whether the auxiliary braking apparatus has fully released the brake of the towed vehicle when supplemental braking is not required. If the brake pedal is not fully retracted during non-use, excess strain is put on the towing vehicle as well as needless wear and tear on the brakes of the towed vehicle. Similarly, operators of the towing vehicle are also generally unaware as to whether such units are working efficiently and/or are about to fail. Thus there is a need for an auxiliary brake system that while in transit, monitors and reports on the efficiency of integral components and indicates whether the brake pedal of the towed vehicle has been fully disengaged during periods of non-use.
Typical RF remote units used in the towing vehicles are powered through a cord interconnected to the towing vehicle's cigarette lighter or other power source. Many problems are associated with this corded configuration however. For example, the operator can become inadvertently entangled in the cord, the cord typically prevents the unit from being placed in the operator's line of sight, and electrical interference with the towing vehicle's electrical system can occur. Thus there is a need for an auxiliary braking system that employs a remote control unit that is powered independently of the towing vehicle's electrical system.
Another drawback is that auxiliary brake systems of the art are often susceptible to operator error. Typically, the auxiliary braking apparatus employs an air reservoir that is fed by an air compressor. Inevitably, the air reservoir remains somewhat pressurized once the unit is disconnected from the power source that feeds the compressor. While the lack of electrical power will generally prevent accidental discharge of the unit, once power is restored to the unit for example, when the device is plugged into a cigarette lighter of the towed vehicle, there is a risk that the unit could immediately activate. Currently known systems attempt to remedy this issue by providing a manually operated bleed valve that allows the operator to alleviate the air pressure when the device is disconnected. There is no way, however, to ensure that the operator will remember to perform this depressurizing step. Thus there is a need for a safer auxiliary braking system that automatically bleeds any residual air from the auxiliary braking apparatus at system shutdown in order to prevent accidental discharge when the apparatus is subsequently powered up.
Another problem inherent to many auxiliary braking systems is that they are designed to be used with a “dead” brake pedal in the towed vehicle. As such, the vacuum associated with the power brakes of many towed vehicles must be relieved before the unit can be effectively used. If the vacuum is not relieved and the auxiliary braking system is activated, excessive braking of the towed vehicle can occur that can damage the towed vehicle. Known systems attempt to address this issue by requiring the user to remember to activate the auxiliary braking apparatus several times to exhaust the vacuum reservoir of the towed vehicle. Thus there is a need for a system that not only reminds the user of this necessary procedure, but also automatically depresses the towed vehicle's brake pedal a number of times to deplete the towed vehicle's vacuum reservoir.
Even if an operator remembers to initially release the vacuum brake reservoir pressure, he or she often later forgets to perform this necessary operation once the auxiliary braking unit has been installed. That is, since many auxiliary brake systems are powered through the cigarette lighter or 12V power source of the towed vehicle, the operator must run the towed vehicle's engine periodically in order to keep the battery adequately charged. Restarting the towed vehicle's engine to recharge the vehicle's battery also recharges the towed vehicle's vacuum reservoir. If not relieved, excessive, unwanted braking could occur in the towed vehicle. Thus, there is a need for a self-contained, auxiliary braking apparatus that informs an operator of the subsequent recharging of the towed vehicle's vacuum reservoir.
Known supplemental brake systems are known as either “proportional” or “on/off” braking systems. Generally, “on/off” (which as used herein is also meant to include “discrete level” systems) systems apply the brakes of the towed vehicle at a preset level when the unit determines that braking is required. Proportional braking systems vary the braking pressure in proportion to the amount of braking occurring in the towing vehicle. There are situations, for example, city versus highway driving, in which drivers prefer to use one braking method over the other. For example, an on/off system will generally not apply towed vehicle braking when the towing vehicle is traveling at low speeds. Thus using a proportional system may be more preferable for city driving conditions wherein slower speeds are typical. To date, however, consumers are required to make a choice between buying an on/off or a proportional system. Thus there is a need for an auxiliary braking apparatus that allows an operator to quickly and easily transition between on/off and proportional braking modes.
Most states require towed items over a certain weight to be equipped with a secondary safety device generally referred to as a “breakaway” system, which is used to brake the towed vehicle, if it separates from the towing vehicle. Auxiliary braking systems of the art meet this requirement by using a breakaway switch. Many operators, however, either forget to install this switch or ignore state mandate. Thus in order to improve consumer safety and compliance with state law, there is a need for a system that detects the absence of a breakaway system and alerts the operator that the breakaway system is absent or malfunctioning.
Another problem inherent to auxiliary brake systems relates to their ability to react and apply the towed vehicle's brakes as quickly as possible. Most vehicle braking systems require at least some inward travel of the brake pedal before actual braking pressure occurs. Conventional auxiliary braking apparatus do not take this non-braking stage into account when applying braking pressure and are thus not as effective as they could be. Thus there is a need for an auxiliary braking unit that applies cylinder/piston extension in such a way to quickly surpass the non-braking stage of travel of the towed vehicle's brake pedal and then reverts to a slower, more suitable braking force for the particular braking application.
The embodiments of the present invention described below represent, among other things, an improvement over known auxiliary braking systems and is designed to overcome the aforementioned problems and other needs.